The present invention relates to a phase adjusting method which, in a work with a recess formed around the axis of the work, positions the recess around the axis of the work. In addition, the present invention also relates to a recess machining apparatus and method for producing a work with a recess formed around its axis in which the recess of the work can be accurately positioned and then machined.
For example, a loading cam mechanism of a troidal-type continuously variable transmission used as a transmission for a car includes a cam disk and a roller. The cam disk is formed in a disk shape which is symmetric with respect to the axis of the cam disk. Also, the cam disk includes an end face, which is formed symmetric with respect to the above-mentioned axis and extends in a flat manner along a direction meeting at right angles to the above-mentioned axis, and a plurality of cam surfaces each of which has a concave shape extending from the end face and is formed at positions spaced at equal intervals along the peripheral direction of the cam disk.
Each of the cam surfaces includes a pair of inclined surfaces respectively formed inclined with respect to the end face of the cam disk and opposed to each other, and an arc surface connecting the pair of inclined surfaces to each other.
To manufacture a work such as the above-mentioned cam disk which includes an end face formed symmetric with respect to the axis of the work and a plurality of cam surfaces respectively formed in a concave manner from the end face of the work and arranged at equal intervals along the peripheral direction of the work, normally, there is employed a manufacturing method which comprises the following two steps: that is, one is a rough machining step in which a cylindrical-shaped blank member is forged or cut to thereby produce once an intermediate product close in shape to the above-mentioned cam disk; and, the other is a finishing step in which a grinding operation or a similar finishing operation is executed on the thus produced intermediate product to thereby obtain a cam disk having a final shape.
The intermediate product 62 (which is hereinafter referred to as a work) obtained through the rough working step, as shown in FIG. 13 and in other figures, is formed in a disk shape which is symmetric with respect to the axis P2 thereof. The work 62 includes an end face 63, which is formed symmetric with respect to the axis P2 and extends in a flat manner along a direction meeting at right angles to the axis P2, and aplurality of recesses 64 which are respectively formed in a concave manner and are disposed at equal intervals along the peripheral direction of the work 62. By the way, these recesses 64 correspond to the above-mentioned cam surfaces.
When carrying out a grinding operation or a similar finishing operation on the work 62 obtained through the rough working step, it is necessary to position a tool such as a grindstone or the like at a position which corresponds to the above-mentioned recesses 64. For this reason, a proper position relationship between the recesses 64 and tool must be maintained by using means which can position or set the position of the recesses 64 around the axis P2 at a given position.
Conventionally, in carrying out a grinding operation or a similar finishing operation on the above-mentioned work 62, to keep a proper position relationship between the recesses 64 and tool, an operator positions the tool such as a grindstone or the like by hand in such a manner that it is contacted with the bottom 64 a of the currently required one of the recesses 64. An operation to position the recess 64 and tool in this manner not only demands skill from the operator but also is liable to lower the positioning accuracy of the work 62 around the axis P2. Further, such positioning operation provides a low operation efficiency and is thus liable to increase the manufacturing cost of the work 62.
As the means for positioning the position of each of the recesses 64 around the axis P2 at a given position, it can be expected to use a positioning jig. A positioning jig of this type includes a projection which can be engaged with and matched to any one of the recesses 64. That is, when using such positioning jig, the projection thereof is engaged with and matched to the specific one of the recesses 64 to thereby position the work 62. However, a phase adjusting method using this type of positioning jig is found that it is liable to lower the positioning accuracy of the work 62 around the axis P2; for example, the positioning accuracy of the work 62 around the axis P2 is easy to vary.
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional phase adjusting method.
Accordingly, it is an object of the invention to provide a phase adjusting method which is able to position each of the recesses of the work around the axis of the work with high accuracy and also to restrict an increase in the manufacturing cost of the work. In addition, it is also an object of the present invention to provide a recess machining apparatus and method for producing a work with a recess formed around its axis with high accuracy and also for restricting an increase in the manufacturing cost of the work.
In attaining the above object, according to the invention, there is provided a phase adjusting method for holding a work with a recess formed around the axis of the work and for positioning the position of the recess around the axis, the method comprising the steps of: holding the work in such a manner that it can be rotated around the axis of the work; detecting the position of the recess around the axis of the work; finding a rotation angle around the axis for positioning the recess at a given position around the axis of the work in accordance with the thus detected position of the recess around the axis of the work; and, rotating the work around the axis thereof in accordance with the thus found rotation angle to thereby position the recess at a given position around the axis of the work.
The above object can be achieved by a phase adjusting method for holding a work with a recess formed around the axis of the work and for positioning the recess around the axis at a predetermined rotational angular position, the method according to the present invention comprising the steps of:
holding the work;
detecting an initial angular position of a detecting point of the work at which a contact sensor is brought in contact with the work;
rotating the work in a first direction until the detecting point reaches a first angular position;
reverse-rotating the work in a second direction opposite to the first direction until the detecting point reaches a second angular position;
calculating an detected angular position on the basis of first and second angular positions and then calculating a rotation angle corresponding to a difference between the initial angular position and the detected angular position; and
adjusting a phase of the recess into a predetermined angular position by rotating the work around the axis in accordance with the rotation angle thus calculated.
In the phase adjusting method according to present invention, it is preferable that the angular position is an averaged angular position of the first and second angular positions. In addition, in the phase adjusting method according to present invention, it is preferable to further comprise the steps of:
supplementally sensing a detecting point before the detecting step but after the holding step, and
rotating the work by 180 degree so as to conduct the detecting step.
Further, the above object can also be attained by a recess machining apparatus for manufacturing a work with recesses disposed in a circumferential direction at a predetermined interval, the recess machining happaratus according to the present invention comprising:
a holding and rotating member by which a work can be held at any angular positions and the work can be rotated around its axis;
a machining unit having a tool by which the recesses of the work can be finally machined;
three dimensional drive unit for driving the machining unit in a X direction horizontally extended along the axis of the work, a Y direction vertically extended along a line perpendicular to the X direction and a Z direction horizontally extended along a line perpendicular to the X and Y directions;
table sensor detecting an angular position of the work about the axis of the work;
position sensors respectively detecting positions of the machining unit in the X, Y and Z directions;
a contact sensor provided with the tool while keeping a predetermined positional relationship between the contact sensor and the tool; and
a phase controller for controlling and adjusting a positional relationship between the tool and an angular position of the recess, wherein
the phase controller brings the contact sensor into contact with a detecting point of the work and then stores an initial angular position of the detecting point at this time,
the phase controller rotates the work in a first direction by a first rotational angular distance and then stores a first data,
the phase controller reverse-rotates the work in a second direction opposite to the first direction by a second rotational angular distance and then stores a second data,
the phase controller calculates an detected angular position on the basis of first and second angular positions and then calculates a rotation angle corresponding to a difference between the initial angular position and the detected position, and
the phase controller adjusts the recess into a predetermined angular position by rotating the work around the axis in accordance with the rotation angle thus calculated.
In the recess machining apparatus, it is advantageous that the first data is a first angular position of the detecting point of the work, the second data is a second angular position of the detecting point of the work, and the phase controller calculates the rotation angle which corresponds to a difference between an averaged angular position of the first and second angular positions.
In the recess machining apparatus, it is advantageous that the work has a positional hole which is disposed apart from the recess by a predetermined distance,
the first angular position is defined by an angle between a line which extends in the Z direction and contains the axis of the work and a line which is formed by connecting the axis of the work and a first contact position where the inner surface of the positional hole and the positional sensor are brought in contact with each other when the work rotates in the first direction, and
the second angular position is defined by an angle between a line which extends in the Z direction and contains the axis of the work and a line which is formed by connecting the axis of the work and a second contact position where the inner surface of the positional hole and the positional sensor are brought in contact with each other when the work rotates in the second direction.
In the above mentioned recess machining apparatus, it may further comprise:
a supplemental sensor which is provided with the contact sensor and disposed at a position apart from the contact sensor by an angle of 180 degree about the axis of the work.
Moreover, in the recess machining apparatus, it is preferable that
each of the recesses is substantially formed into a symmetrical V-shape defined by first and second inclined lines in a cross-section,
the first predetermined rotational angular distance is equal to the second predetermined rotational angular distance,
the contact sensor is brought in contact with a point of the work which is contained in its predetermined pitch circle,
the first data is a first height of a first detecting point on the first inclined line, in the X direction detected by the X direction position sensor, the first detecting point being a point at which the first inclined line and the contact sensor are contacted with each other when the work is rotated in the first direction, and
the second data is a second height of a second detecting point on the second inclined line, in the X direction detected by the X direction position sensor, the second detecting point being a point at which the second inclined line and the contact sensor are contacted with each other when the work is rotated in the second direction.
The above object can further be achieved by recess machining method for manufacturing a work with recesses disposed in a circumferential direction at a predetermined interval, in a recess machining apparatus comprising a holding and rotating member by which a work can be held at any angular positions and the work can be rotated around its axis, a machining unit having a tool by which the recesses of the work can be finally machined, three dimensional drive unit for driving the machining unit in a X direction horizontally extended along the axis of the work, a Y direction vertically extended along a line perpendicular to the X direction and a Z direction horizontally extended along a line perpendicular to the X and Y directions, a table sensor detecting an angular position about the axis of the work, position sensors respectively detect positions of the machining unit in the X, Y and Z directions, a contact sensor provided with the tool while keeping a predetermined positional relationship between the contact sensor and the tool, and a phase controller for controlling and adjusting a positional relationship between the tool and an angular position of the recess, the recess machining method according to the present invention comprising the steps of:
bringing the contact sensor into contact with a detecting point of the work and then storing an initial angular position of the recess at this time,
detecting the initial angular position of a detecting point of the work at which a contact sensor is brought in contact with the work
rotating the work in a first direction by a first rotational angular distance and then storing a first data at this time,
reverse-rotating the work in a second direction opposite to the first direction by a second rotational angular distance and then storing a second data at this time,
calculating an detected angular position of the detecting point of the work on the basis of first and second data and then calculating a rotation angle corresponding to a difference between the initial angular position and the detected angular position, and
adjusting the recess into the predetermined angular position by rotating the work around the axis in accordance with the rotation angle thus calculated.
In the recess machining method, it is preferable that the first data is a first angular position of the work, the second data is a second angular position of the work, and the phase controller calculates the rotation angle which corresponds to a difference between an averaged angular position of the first and second angular positions.
Further, in the recess machining method, it is preferable that
the work has a positional hole which is disposed apart from the recess by a predetermined distance,
the first angular position is defined by an angle between a line which extends in the Z direction and contains the axis of the work and a line which is formed by connecting the axis of the work and a first contact position where the inner surface of the positional hole and the positional sensor are brought in contact with each other when the work rotates in the first direction, and
the second angular position is defined by an angle between a line which extends in the Z direction and contains the axis of the work and a line which is formed by connecting the axis of the work and a second contact position where the inner surface of the positional hole and the positional sensor are brought in contact with each other when the work rotates in the second direction.
Furthermore, in the recess machining method, it is preferable to further comprises the step of:
preliminary detecting a phase of the recess with a supplemental contact sensor which is provided with the contact sensor and disposed at a position apart from the contact sensor by an angle of 180 degree about the axis of the work.
Moreover, in the recess machining method, it is also advantageous that
each of the recesses is substantially formed into a symmetrical V-shape defined by first and second inclined lines in a cross-section,
the first predetermined rotational angular distance is equal to the second predetermined rotational angular distance,
the contact sensor is brought in contact with a detecting point of the work which is contained in its predetermined pitch circle,
the first data is a first height of a first detecting point on the first inclined line, in the X direction detected by the X direction position sensor, the first detecting point being a point at which the first inclined line and the contact sensor are contacted with each other when the work is rotated in the first direction, and
the second data is a second height of a second detecting point on the second inclined line, in the X direction detected by the X direction position sensor, the second detecting point being a point at which the second inclined line and the contact sensor are contacted with each other when the work is rotated in the second direction.
According to the present phase adjusting method and the present recess machining apparatus and method, the work is held in such a manner that it can be rotated around the axis thereof, the position of the recess around the axis of the work is detected and, in accordance with the thus detected recess position, there is obtained a rotation angle which is used to position the recess at a given position. And, in accordance with the thus obtained rotation angle, the work is rotated around the axis thereof and is thereby positioned. Thanks to these methods and apparatus, the work can be positioned around the axis thereof with high accuracy.
Also, due to the fact that, based on the detected position of the recess, there is obtained the above-mentioned rotation angle and, based on this rotation angle, the work is rotated around the axis thereof and is thereby positioned, an operation to position the work can be automated. This makes it possible to restrict an increase in the production cost of the work and the like.
The above object can be achieved by a recess machining apparatus for manufacturing a work with recesses disposed in a circumferential direction at a predetermined interval, said recess machining apparatus comprising:
a holding and rotating member by which a work can be held at any angular positions and work can be rotated around its axis;
a machining unit having a tool by which recesses of work can be finally machined;
three dimensional drive unit for driving relatively machining unit and holding and rotating member in a X direction horizontally extended along the axis of work, a Y direction vertically extended along a line perpendicular to X direction and a Z direction horizontally extended along a line perpendicular to X and Y directions;
table sensor detecting an angular position of work about the axis of work;
position sensors respectively detecting positions of the machining unit in the X, Y and Z directions;
a contact sensor provided with tool while keeping a predetermined positional relationship between contact sensor and tool; and
a phase controller for controlling and adjusting a positional relationship between tool and an angular position of recess, wherein
each of recesses is substantially formed into a symmetrical V-shape defined by first and second inclined lines in a cross-section,
first predetermined rotational angular distance is equal to second predetermined rotational angular distance,
contact sensor is brought in contact with a point of work which is contained in its predetermined pitch circle,
first data is a first height of a first detecting point on first inclined line, in the X direction detected by X direction position sensor, first detecting point being a point at which first inclined line and contact sensor are contacted with each other when work is rotated in the first direction, and.
second data is a second height of a second detecting point on second inclined line, in the X direction detected by X direction position sensor, second detecting point being a point at which second inclined line and contact sensor are contacted with each other when work is rotated in the second direction, and
phase controller determines a reference angular position of table sensor on the basis of first predetermined rotation angular distance, first data and second data.
In addition, the above-mentioned object can further be attained by a recess machining method for manufacturing a work with recesses disposed in a circumferential direction at a predetermined interval, in a recess machining apparatus comprising a holding and rotating member by which a work can be held at any angular positions and work can be rotated around its axis, a machining unit having a tool by which recesses of work can be finally machined, three dimensional drive unit for driving relatively machining unit and holding and rotating member in a X direction horizontally extended along the axis of work, a Y direction vertically extended along a line perpendicular to X direction and a Z direction horizontally extended along a line perpendicular to X and Y directions, a table sensor detecting an angular position about the axis of work, position sensors respectively detect positions of the machining unit in the X, Y and Z directions, a contact sensor provided with tool while keeping a predetermined positional relationship between contact sensor and tool, and a phase controller for controlling and adjusting a positional relationship between tool and an angular position of recess, recess machining method comprising the steps of:
bringing contact sensor into contact with a detecting point of work and then storing an initial angular position of recess at this time,
detecting initial angular position of a detecting point of work at which a contact sensor is brought in contact with work
rotating work in a first direction by a first rotational angular distance and then storing a first data at this time,
reverse-rotating work in a second direction opposite to first direction by a second rotational angular distance and then storing a second data at this time,
calculating an detected angular position of detecting point of the work on the basis of first and second data and then calculating a rotation angle corresponding to a difference between initial angular position and detected angular position, and
adjusting recess into predetermined angular position by rotating work around axis in accordance with rotation angle thus calculated,
wherein
each of recesses is substantially formed into a symmetrical V-shape defined by first and second inclined lines in a cross-section,
first predetermined rotational angular distance is equal to second predetermined rotational angular distance,
contact sensor is brought in contact with a detecting point of work which is contained in its predetermined pitch circle,
first data is a first height of a first detecting point on first inclined line, in the X direction detected by X direction position sensor, first detecting point being a point at which first inclined line and contact sensor are contacted with each other when work is rotated in the first direction, and
second data is a second height of a second detecting point on second inclined line, in the X direction detected by X direction position sensor, second detecting point being a point at which second inclined line and contact sensor are contacted with each other when work is rotated in the second direction, and
phase controller determines a reference angular position of table sensor on the basis of first predetermined rotation angular distance, first data and second data.